Insomnia is a prominent complaint in late-life. However, little scientific effort has been directed toward identifying the biological mechanisms that are related to abnormal sleep or to evaluating the efficacy of behavioral treatments for insomnia in older adults. Basic observations demonstrate that proinflammatory cytokines play a key role in the regulation of sleep. Our translation of cytokine-sleep mechanisms into the clinic show that cytokines are reciprocally linked with abnormal sleep. The proposed research builds upon these findings and extends a program of study that has examined the efficacy of behavioral interventions on health outcomes in the elderly. Preliminary studies show found that Tai Chi Chih (TCC), a slow moving meditation, contributes to improvements in subjective sleep quality, sleep amounts and sleep efficiency, alterations in sympathetic activity, decreases in proinflammatory cytokines, and improvements in health functioning in community-dwelling older adults. Additionally, cognitive behavior therapy (CBT) confers benefits on sleep outcomes. In this randomized, controlled trial, 150 older adults will be randomly assigned to CBT, TCC, or sleep hygiene/ education control (EC) over 16 weeks and followed for one year. The aims of this project are to: 1) evaluate the effects of CBT vs TCC vs. EC on objective and subjective measures of sleep and on fatigue, mood, and health functioning in older adults with insomnia; 2) determine the effects of CBT vs.TCC vs. EC on measures of proinflammatory cytokine activity and sympathovagal balance, and whether these two biological mechanisms are related to changes of disordered sleep over the course of the treatment trial; and 3) evaluate whether circulating levels of proinflammatory cytokines are associated with measures of sleep continuity in older adults with insomnia over the treatment trial. This study will advance psychobiological models of disordered sleep and the potential benefits of two readily exportable behavioral interventions for promoting improvements in sleep outcomes in the elderly.